Crad can't top this - oil change fitting

[AirTool]

Later today I'm going to stop by Grainger and pick up this swivel NPT fitting to attach between my suck up and the mnpt connection on my Excalibur's oil drain hose.

It is going to make oil changes SO EASY. The swivel on the fitting will allow me to easily tighten the connection without having to disconnect the hose or flip the hose round and round. I thought of using air hose disconnects but I'm thinking they won't seal under vacuum.

I usually let the oil drain overnight to get it out of every nook and cranny. But with this method, I'll probably change it more frequently because it will be so much easier and I won't have to go back the next day. I think I'll crack loose the oil filter as soon as I pull out of the water to let a little air in ...then tighten it back. That way the siphon will break and most of the oil in the remote hoses can drain to the sump. That is usually the biggest problem (besides the sloooow drain rate) and there is a lot of oil in there.

http://www.grainger.com/Grainger/wwg...rue&sst=subset

[DanielC]

I think I'll crack loose the oil filter as soon as I pull out of the water to let a little air in ...then tighten it back."
This will not make much of difference in how fast the oil comes out of the engine. One hose goes to the oil pump. It is a positive displacement pump, no oil goes through it unless it is turning, and that does not happen unless the engine is running.
The other hose goes to the oil galleys, and eventually to the crankshaft, and other bearings in the engine. All these bearings have pretty tight clearances.

The crankcase of the engine is vented by the PCV valve. When the engine is running, this valve draws crankcase fumes into the intake manifold, usually mounted on one valve cover. The other valve cover is open to the atmosphere. So you really cannot draw a vacuum on the crankcase, to help suck the oil out of the oil galleys.

My recommendation, suck the oil out of the crankcase when it is hot. This still leaves oil in the oil galleys, and filter. Waiting overnight will let this oil drain back into the oil pan, except for the oil between the filter, and oil pump. The oil in the other oil line will slowly drain through the crankshaft bearings, and into the pan. One concern, in draining the oil and letting the oil lines, and galleys run out overnight is it leaves a lot of air in the oil lines. I definitely would recommend you fill the the new oil filter with fresh oil through the center hole before you put it on the engine.

[AirTool]

I am a big fan of letting the oil drain overnight. But it is a PITA. I don't let my trucks drain overnight and the oil looks new after an oil change. In my boat, I changed the oil quickly a couple of times and the oil looked 10 hours old after the first warm up. If I followed the overnight procedure, the oil looked new after the change. So I've followed and promoted the overnight procedure. Many posts reflect that.

I would like to find a way to get a great oil change without having to drain the pan overnight.

Here are some comments:

I think I'll crack loose the oil filter as soon as I pull out of the water to let a little air in ...then tighten it back."
This will not make much of difference in how fast the oil comes out of the engine.

I agree it will make no difference at all in how fast the oil comes out of the engine. But if I were to drain the pan rapidly (with the aid of a suck-up) and cap the drain before the remote oil reported back to the pan, then the remote oil would not be replaced during said oil change. Giving the remote oil more time to report to the pan before the pan is closed up increases the chance that those molecules are changed during said oil change and not the next one. I know you will agree with that statement because you recommend letting the pan drain all night.

One hose goes to the oil pump. It is a positive displacement pump, no oil goes through it unless it is turning, and that does not happen unless the engine is running. The other hose goes to the oil galleys, and eventually to the crankshaft, and other bearings in the engine. All these bearings have pretty tight clearances.

So the line to the lubed components will drain but at a slow rate. It will drain sooner/faster (and perhaps only) if air is introduced into the line to break its vacuum. I believe the line from the pump will also drain back through the positive displacement pump in spite of its tight clearances and that the oil would drain sooner/faster (and perhaps only) if air is introduced into the line at the filter housing. I do not know if there is a check valve in the pump so I'm going to go with your assumption that it doesn't drain although I am pretty sure that it does drain.

The crankcase of the engine is vented by the PCV valve. When the engine is running, this valve draws crankcase fumes into the intake manifold, usually mounted on one valve cover. The other valve cover is open to the atmosphere.

I am fully aware of the Positive Crankcase Ventilation Valve and appreciate its existence. Do note, though, that the PCV Valve is a one way check valve that allows the intake system to extract vapor from the crankcase but the valve actually as a gravity weighted poppet that seals to prevent reverse flow. That type of valve would allow a vacuum to be pulled on the crankcase in a situation where the valve opening was the only opening to the atmosphere.

So you really cannot draw a vacuum on the crankcase, to help suck the oil out of the oil galleys.

I have no intention of drawing a vacuum on the crankcase and I don't believe I suggested that.

My recommendation, suck the oil out of the crankcase when it is hot.

I agree.

This still leaves oil in the oil galleys, and filter. Waiting overnight will let this oil drain back into the oil pan, except for the oil between the filter, and oil pump. The oil in the other oil line will slowly drain through the crankshaft bearings, and into the pan.

I believe if I break the vacuum in the filter before I leave the boat ramp, at least the one hose would drain before I get to the barn. (I believe both hoses drain, but I gave you that one.) Either hose that drains should drain pretty fast because the viscosity of the oil is so low due to its high temperature. Several minutes should be adequate. If the one hose won't drain through the pump (as you suggest) it won't matter how long one waits....even overnight.

One concern, in draining the oil and letting the oil lines, and galleys run out overnight is it leaves a lot of air in the oil lines. I definitely would recommend you fill the the new oil filter with fresh oil through the center hole before you put it on the engine.

I agree, but priming the filter with oil and installing it is not a feasible task. The filter has to be tilted some to get it on the adapter. So one can't fill the filter all the way up and then install it without spilling oil. Half full probably doesn't provide much value. I usually pull the lanyard and crank the engine a few times to prime at least the pump before. Perhaps oil makes it all the way through the filter using this procedure. Maybe some day I'll pull the filter back off and check it. There would be very little wear/harm done to the engine during a cranking only operation. There is little pressure in the cylinder to create the forces and there is no heat. The residual oil film should provide adequate lubrication for a few cranks.

So I have data for two cases:

Case 1: fast gravity drain through hose (fast being an hour or so). The results are lousy and the new oil looks 10 hours dirty after the first use.

Case 2: overnight drain through hose. The results are great and this has produced the highest volume of oil to discard.

The next case (Case 3) is the one I described in the first post (expediting the filter hoses to drain) and using the suck up to speed the draining of the pan after the filter hoses have drained.

After executing Case 3, I will report back how I feel about the amount of old oil that didn't get drained.

I can't do it this weekend because Grainger closed at 5 !!!!

[AirTool]

Yipeee!!!

I got my fitting from Grainger today. Not as sick as Crad's new ride...but it was only 10 bucks and I didn't have to bargain with my wife.

Sad part is that it is two pieces and falls apart when not on the hose. I think I'll just run a small o-ring up the barb to hold the nut.